Attack on Pearl Harbor (5 page)

Engaging there would be difficult, at the end of their fuel tether and with tired crews. The Japanese fleet had few salvage and repair ships to forward deploy to recover the detritus of the battle, because they were not needed under the previous concept of operations. Planning for battle further forward also meant it would happen earlier along the American’s advance, leaving the Japanese less time to achieve and consolidate their gains and less time for the Interceptive Operations to work.

Why would Yamamoto agree to move the decisive battle out so far? It is likely that he acceded to the entreaties of the Naval General Staff
before
the war because he felt that such plans would be swept away as the war unfolded. Yamamoto was skeptical of the “formalistic view of tactics” that was held by the Naval General Staff. During a study meeting in 1940 he said, “Don’t you think the Naval General Staff’s idea of attritional operations relying fifty percent on submarines is a bit risky? I can’t really believe that the idea of bringing them out to fight would work.” He believed that a war centered on a “leisurely battleship sortie” just would not happen.
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If events did not cooperate with the Naval General Staff’s scenario, Yamamoto could declare that the final decisive battle would occur in the Marshalls or Carolines or on the dark side of the moon, and it would be smoke in the wind. He could administratively announce agreement with the Naval General Staff while knowing in his heart that such announcements were irrelevant—the strategy would be, in modern US Navy parlance, OBE, “Overtaken By Events.”

Meanwhile, the Naval General Staff persisted in believing they had a fair chance of success in this new, more distant Decisive Battle, while awkwardly acknowledging that there was no sure means of forcing such an encounter.
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Inter-service politics also intruded. The Imperial Japanese Navy’s (IJN) commitment to fight the Decisive Battle far forward meant the Navy would fully support the Army’s Southern Advance, and not abandon them to being bypassed and isolated while it was squatting on its conquests.

In one seminar after a joint Army-Navy wargame, an officer raised the possibility that the Americans might do something other than make a move to relieve the Philippines—for example, they might immediately launch an attack against the Japanese mainland. Surely different eventualities should also be studied? A Naval General Staff officer supervising the maneuvers replied:

The War in Europe’s Impact on Pacific Fleet Strategy

On the American side, the ORANGE warplan was superseded by the RAINBOW series, which looked to a world war. It opens with a statement of overwhelming significance to the Pacific Fleet:

As a secondary effort, the Pacific Fleet was to act “offensively in the manner best calculated to weaken Japanese economic power, and to support the defense of the Malay Barrier.” A “vigorous offensive,” with “bold aggressive action,” was desired.
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These clarion calls were stirring in principle, but in practice would be difficult. More of the Pacific Fleet was siphoned off for Atlantic duty, scheduled arrivals of amphibious shipping and troops were delayed or redirected, merchant shipping became scarce, and the Pacific Fleet so starved for oilers that its radius of action was curtailed. With fewer ships, fewer Marines, and fewer auxiliaries, the idea of taking Truk by day 59 or day 75 or even day 180 was clearly impossible. RAINBOW forced a “long war” strategy on the Pacific Fleet.

Regardless, Admiral Kimmel, the Commander in Chief of the Pacific Fleet, planned for offensive action with carriers and battleships operating against the Marshalls, commencing only a few days after the beginning of hostilities. In addition to raiding, Kimmel had a rather fantastical plan to lure the Japanese fleet into battle by offering his aircraft carriers as bait.

Kimmel knew the Japanese would have to come to him, as he could not go to them. It would be hard for his force to work further to the west than the Mandates. The Pacific Fleet had four oilers equipped for underway replenishment of warships, but needed 25 for extended operations.
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With the war in Europe’s insatiable appetite for shipping, and the German U-boat offensive sinking dozens of ships every month—while the American public was still addicted to its Sunday afternoon drives—shipping, particularly oilers, would be hard to snatch away.

Logistics, Forward Bases and “Unsinkable Aircraft Carriers”

If the Japanese were not totally blind to logistics, they were at least vision-impaired. They operated their forces with the barest minimum logistics support, often beginning operations with insufficient supplies to carry them through to completion. The construction of warships was always a higher priority than auxiliaries. Logistics concerns were secondary when constructing their outer lines of defense in the Pacific.

Some of the Japanese neglect stemmed from treaty restrictions. As a reward for participating in World War I, the Japanese were given the Mandate Islands in the Pacific under the League of Nations. As a price for accepting the 10:6 ratio in the Washington Naval Treaty, the Japanese insisted on a ban on fortifications in Pacific areas, denying Western powers forward support bases to operate against Japan (Article XIX). Eliminating fortifications matched both their needs and their inclinations, as it prevented a “base development race” in the Pacific that the Japanese wanted to avoid financially as well as strategically. Even after the Japanese abrogated their participation in the naval treaties and withdrew from the League of Nations, their concept of operations, where they expected to lose their outlying possessions during an attrition phase of the American advance, marked these possessions as expendable. Base development would be limited to the bare necessities to support attrition operations against the American advance.

For example, Truk, the Fourth Fleet’s base from November 1939, was the strongest Japanese naval base in the Pacific. However, the Japanese “Gibraltar of the Pacific” had minimal shore repair facilities. Fuel storage was totally inadequate, eventually consisting of one 10,000-ton capacity underground tank and two above-ground 50 meter diameter by 20 meter high (250,000 bbl, 33,600 ton) steel tanks, a total storage capacity of 77,200 tons. The remains of these tanks can be seen today, though it is not known exactly when they were constructed.

To place this capacity in context, to fill one battleship would take about 5,000 tons of fuel, a heavy cruiser about 2,500 tons. If just the Japanese battleships and heavy cruisers of the Combined Fleet arrived, the fuel storage at Truk could not give them all a single ship fill. The 77,200 tons of fuel storage can be compared to the Americans’ forward base in the Pacific, Pearl Harbor, with storage for 563,000 metric tons of fuel with additional capacity under construction.

During the war the IJN anchored tankers in Truk Lagoon as fuel storage “station ships.” Instead of moving fuel the tankers acted as floating storage tanks, a burden on the limited Japanese tanker fleet.
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Insufficient fuel transportation would be one of the three greatest causes of the defeat of the Japanese (the others being the inadequate wartime replacement of pilots, and the starvation of industry by the destruction of Japan’s maritime transport).

The attitude of the Japanese to logistics is exemplified by an anecdote from one of their chart exercises. A unit was being advanced to contact with the enemy. To save fuel for high-speed operations in the vicinity of the opposing fleet, a slow speed of advance was initially dictated. This was criticized. The advance lacked “alacrity.” Too much worry over fuel made “proper” maneuvers impossible. When forces were calculated as out of fuel, they were simply assumed to have been refueled at sea, and the swift advance continued.
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Logistics considerations were similarly ignored when making strategy. For example, in early January 1942 the Naval General Staff performed a study on invading, capturing, and sustaining a Japanese garrison in the Hawaiian Islands. Three million tons of cargo would be required to feed the islands’ population over a year’s time, and 30 ships per month to transport military equipment, a total of 60 shipments a month. A nine-knot freighter would take 36 days to make the round trip in transit time alone, not counting loading and unloading time and ship’s maintenance and time spent awaiting escorts. The study concluded that Japan’s overstressed merchant marine could not meet the requirement. This study did not consider that the food might not even be available from Japan, as food shortages were already a serious topic of conversation in homes throughout the Empire.
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Obtaining food supplies directly from Indochina might double the shipping requirement.

In spite of this, members of the Japanese high command continued to advocate an invasion of Hawaii. One month after the Doolittle raid, the army joined in the decision to seize Hawaii.
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Only the Battle of Midway put an end to their Hawaiian ambitions.

Mirror Imaging

Just as the Japanese tended to gloss over logistics concerns when making their own strategies, they tended to ignore logistics limitations confronting the enemy. The attitude of “mirror imaging” deserves mentioning. In mirror imaging, a side projects onto the enemy its own attitudes and beliefs and capabilities. In some ways this is a conservative viewpoint. Each navy tended to believe its intellectual foundation and abilities were superior to that of the enemy. If your own abilities are projected onto the enemy in a map maneuver or force calculation, and the enemy allowed to use your own concepts of operations, then you are attributing to them the “best” capabilities. If you can defeat them under those assumptions, you ought to be able to defeat them even with more assurance under actual conditions—presuming that the enemy was really inferior in that area as supposed, and they do what you expect them to do.

Both the Americans and the Japanese tended to mirror image. For example, on the American side, intelligence was rare on the performance and characteristics of Japanese warships and weapons. With no information on the performance of the Japanese 41cm (16.14-inch) guns mounted on the
Nagato
class battleships, the Americans simply assumed that it performed as well as the equivalent US 16-inch gun. When US Navy intelligence got their first sniffs of the construction of the
Yamato
-class battleships, they projected they would be quite similar to the Americans’
Iowa
-class, with 16-inch guns in triple mounts and just about the same tonnage and speed. A year after the Japanese introduced the 24-inch Type 93 “Long Lance” torpedo, Navy intelligence dismissed the idea that the Japanese could have developed an oxygen torpedo, because the Navy’s Bureau of Ordinance declared such a weapon to be impossible. “Neither the British nor the Americans had yet mastered oxygen technology, so it was inconceivable that the Japanese had done so.”
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Often this was done consciously. For example, a secret publication from 1944 dealing with the damage resistance characteristics of ships stated:

In fact, this assumption was not very good. Japanese warships were optimized for speed and offensive power, and had considerably less resistance to damage and less damage control capability than comparable US Navy ships.
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The Japanese mirror imaged when they assumed that American land-based air would be primarily directed against ships (as was the IJN’s land-based air), that American submarines would be primarily used against warships in the same doctrine as Japanese submarines, and that the American move to the western Pacific would contain the same slapdash, “damn the logistics, full speed ahead!” neglect as the Japanese displayed in their own strategies.

For the Japanese, this also extended to a lack of flexibility in their assumptions, a “self-deluding formalism which assumed that the enemy would act according to predetermined conventions.”
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Anyone questioning orthodoxy was slapped down.

Development of Forward Bases and Mobile Repair Capability

Because of a lack of materials and the ships to transport them, most development of forward bases used local materials and hand labor by the garrison. The paucity of shipping meant that many islands were chronically short of food, fuel, and stores; materials for fortifying a base were sent in bulk only when a particular location was considered “next in line” for Allied attack.

Minimal also, when measured against American standards, was Japan’s maritime development of Truk. Greater additional fuel storage and other facilities at Truk were certainly warranted. Some were built as the war progressed. Rather than providing piers, the fleet anchored in the lagoon. Supplies were delivered using small lighters. Having no piers or shore services—including steam, electricity, and potable water—meant the ships were constantly providing their own services, placing more wear and tear on their engineering plants, and having less availability for maintenance, less rest for the engineers, and a constant drain on the ships’ fuel. Shore services could have been run on coal, which the Japanese had in abundance. Plus, coal did not require large (and vulnerable) storage tanks and pumps and piping. At Truk, the Japanese simply dumped coal in a heap near to where it was needed.